Chapter 13.3, Problem 33E

a.

To determine

Find the predicted value of thrust efficiency y when the divergence angle is 20 and when x is 25.

b.

To determine

Find the estimated regression equation for the unstandardized model.

c.

To determine

Identify whether the cubic predictor should be deleted from the model.

d.

To determine

Explain what can be concluded about the relationship between SSE’s and $R^2\text{'}\text{s}$ for the standardized and unstandardized models.

e.

To determine

Compute the $R^2$ value for each model.

Identify whether the difference between the two $R^2$ values convey that the cubic term could be deleted.